The present invention is directed to a dental handpiece which includes a drive motor part with a motor having a drive shaft being mounted for rotation in a housing, and a grip section, which has a head part with a socket for mounting a tool for rotation, being coupled to the housing and having a drive shaft section coupled to the drive shaft of the motor to transfer rotary motion from the motor to the socket.
In a dental practice, there exists a requirement of being able to disinfect and/or sterilize as needed the parts of the drive motor, which parts come into contact with the fingers of the dentist or technician. Since the drive motor, which is usually an electric motor, is not suited for being disinfected by being placed in a disinfecting liquid or to be sterilized by being placed in an autoclave and being subjected to superheated steam, it has been suggested to protect the motor against contact and thus against contamination by providing an extended sleeve portion on the grip section which has the head part and is coupled to the drive motor part so that the extended sleeve surrounds the motor at least over the most significant part of its length. An example of this device is disclosed in German O.S. No. 1,766,056.
A disadvantage of this type of a solution is that the grip section becomes relatively long and unwieldy. Since the sleeve-like extension is a component part of the handpiece, it must be provided for practically every handpiece. Since a sterilization or disinfection of the drive motor is not constantly required in all dental practice but rather only during specific treatments for example in surgical operations, the added expense of providing each of the grip sections with this sleeve-like extension for covering the motor is not justified.